1. Technical Field
The present invention relates to a substrate processing apparatus and a semiconductor device manufacturing method, and more particularly, to a substrate processing apparatus and a semiconductor device manufacturing method for processing a substrate using plasma.
2. Related Art
A film forming process of depositing a predetermined thin film on a substrate by the use of a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) method using plasma is known as a semiconductor device manufacturing process (see Japanese Patent Application Laid-Open (JP-A No. 2003-297818). A CVD method is a method of depositing a thin film having elements included in source gas molecules as constituent elements on a substrate by the use of a gas phase of a gaseous raw material and a reaction on a surface. In the CVD method, plural types of source gas including plural elements constituting a film to be formed are simultaneously supplied to a substrate to form a film. In the ALD method, plural types of source gas including plural elements constituting a film to be formed are alternately supplied to a substrate to form a film. In the CVD method, the substrate can be processed at a low substrate temperature. The deposition of a thin film is controlled at an atomic layer level in the ALD method. Plasma is used to promote a chemical reaction of a thin film deposited by the use of the CVD method or to remove impurities from the thin film. In the ALD method, plasma is used to assist a chemical reaction of adsorbed film-forming materials.
However, with the gradual finer design rules in manufacturing a semiconductor device, there has been demand to form a film at a low substrate temperature and it is necessary to raise RF power for forming plasma. When the RF power for forming plasma is raised, damage to a substrate or a film to be formed increases, which is not preferable.